Gale Warning 48, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
532 AM AKDT FRI AUG 15 2014

.DISCUSSION...

00Z MODEL GUIDANCE IS IN GOOD AGREEMENT THROUGH THE FORECAST
PERIOD. THE LATEST SUCCESSIVE RUNS OF THE NAM HAVE COME INTO
ALIGNMENT WITH THE GFS AND ECWMF REGARDING THE SIGNIFICANT
RAINFALL EVENT FOR LATER TODAY AND INTO THE COMING WEEKEND.
MODEL GUIDANCE AGREEMENT EXTENDS INTO THE EXTENDED FORECAST
PERIOD...WHERE BOTH THE GFS AND ECWMF HINT AT A RIDGE BUILDING
NORTH AND OVER SOUTHERN ALASKA.

ALOFT...545 DAM LOW PRESSURE OVER NORTHERN ALASKA PENINSULA THIS
MORNING WILL MOVE NORTH OVER SOUTHWEST ALASKA AND WEAKEN LATER
TODAY. ANOTHER LOW WILL MOVE ALONG THE ALEUTIAN ISLAND CHAIN
TODAY AND UP THE ALASKA PENINSULA SATURDAY. A SHORTWAVE IN THE
FLOW ALOFT WILL MOVE ONSHORE IN SOUTHERN ALASKA THIS
AFTERNOON...THEN SHIFT NORTH AND OVER THE INTERIOR LATER
TONIGHT...AND OVER THE BROOKS RANGE SATURDAY.

AT THE SURFACE...SEVERAL TROUGHS RESIDE OVER ALASKA THIS
MORNING...ONE DRAPED ALONG THE BROOKS RANGE...ANOTHER EXTENDING
FROM SOUTHWEST ALASKA...OVER FAIRBANKS...AND TO THE NORTH OF
EAGLE. WEAK AREA OF LOW PRESSURE AND ASSOCIATED OCCLUSION
EXTENDING ALONG THE GULF OF ALASKA COAST MOVING ONSHORE THIS
MORNING. THIS OCCLUSION WILL BE NORTH OF THE ALASKA RANGE THIS
AFTERNOON...THEN SOUTH OF THE BROOKS RANGE BY SATURDAY MORNING.
1023 MB HIGH PRESSURE OVER THE ARCTIC OCEAN WILL DRIFT EAST AND
OVER THE CANADIAN ARCHIPELAGO THROUGH SUNDAY.

NORTH SLOPE...THE PRESSURE GRADIENT ALONG THE ARCTIC COAST WILL BE
MAINTAINED BETWEEN THE ARCTIC HIGH PRESSURE AND TROUGH OVER THE
BROOKS RANGE TODAY...KEEPING STRONG EASTERLY WINDS GOING. EASTERLY
WINDS WILL INCREASE FOR THE EASTERN BEAUFORT SEA COAST SATURDAY
MORNING AS THE OCCLUSION MOVES NORTH TO THE BROOKS RANGE. STRONG
WIND HEADLINES HAVE BEEN ADDED FOR ZONES 203 THROUGH THIS EVENING
AND FOR ZONE 204 STARTING THIS AFTERNOON. AS THE HIGH PRESSURE
DRIFTS TO THE EAST THIS WEEKEND...GRADIENT WILL RELAX...ALLOWING
FROM EASTERLY WINDS TO WEAKEN FROM WEST TO EAST ALONG THE ARCTIC
COAST LATER THIS WEEKEND.

WESTERN ALASKA...VERY ISOLATED CONVECTION YESTERDAY ALONG THE WEST
COAST. EXPECTING CONVECTION TO INCREASE TODAY AHEAD OF THE
NORTHWARD MOVING OCCLUSION. LIFTED INDICES ARE -1 TO -2 AND CAPE
UP TO 350 J/KG THIS AFTERNOON AND EVENING STRETCHING FROM THE
KUSKOKWIM DELTA TO THE SEWARD PENINSULA AND EAST INTO MIDDLE YUKON
VALLEY...SUPPORTING THE DEVELOPMENT OF ISOLATED TO SCATTERED
THUNDERSTORMS. CONVECTIVE POTENTIAL WILL CONTINUE THROUGH THE
WEEKEND...ESPECIALLY OVER THE SEWARD PENINSULA WHERE SCATTERED
THUNDERSTORMS ARE POSSIBLE.

EASTERN AND CENTRAL INTERIOR...OCCLUSION MOVING NORTH FROM
SOUTHERN ALASKA WILL CAUSE SOME SIGNIFICANT RAIN OVER THE EASTERN
AND NORTHERN INTERIOR TO DEVELOP LATER TODAY AND CONTINUE INTO
EARLY SUNDAY. UP TO 1 INCH OF RAIN IS POSSIBLE OVER THE UPLANDS
NORTH OF FAIRBANKS...YUKON FLATS AND THE FORTYMILE COUNTRY. ALONG
THE SOUTHERN SLOPES OF THE EASTERN BROOKS RANGE...1 TO 2 INCHES IS
POSSIBLE THROUGH EARLY SUNDAY. IN ADDITION TO HEAVY
RAIN...ISOLATED TO SCATTERED THUNDERSTORMS ARE POSSIBLE TODAY OVER
MUCH OF THE INTERIOR.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE

&&

.FIRE WEATHER...

INCREASED THREAT OF LIGHTNING WITH SCATTERED THUNDERSTORMS THIS
AFTERNOON AND EVENING FOR PARTS OF WESTERN ALASKA WHERE FUELS
REMAIN BURNABLE. ISOLATED TO SCATTERED THUNDRSTORMS ALSO POSSIBLE
FOR THE INTERIOR TODAY. WINDS WILL REMAIN GUSTY NEAR THE ALASKA
RANGE THROUGH SATURDAY WITH RELATIVE HUMIDITY APPROACHING 30
PERCENT...THOUGH NO CONCERNS SINCE FUELS REMAIN NOT BURNABLE.

&&

.HYDROLOGY...
RISES ON SMALL STREAMS EXPECTED WITH SIGNIFICANT RAIN EVENT LATER
THIS AFTERNOON THROUGH SATURDAY MORNING FROM FAIRBANKS TO FORT
YUKON AS WELL AS THE FORTYMILE COUNTRY. AS BAND MOVES NORTH
SATURDAY...EXPECTING RISES ON SMALL STREAMS IN THE UPPER KOYUKUK
VALLEY AND THE SOUTHEASTERN BROOKS RANGE INTO SUNDAY.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR PKZ230-PKZ235-PKZ240-PKZ245.

GALE WARNING FOR PKZ245.
&&

LTH AUG 14